Effect of Topographic Factors on Gully Initiation (Case study: Dareshahr Area-Ilam Province)
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Banafsheh Yasrebi * , Farhad Nourmohammadi , Seyyed Hamidreza Sadeghi , Majid Soufi  |
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Abstract: (11520 Views) |
Gully erosion is an important feature in Dareshahr, Ilam Province. The present study therefore aimed to recognize the watershed characteristics affecting gully development and the dominant processes in gully initiation. Towards this attempt, 18 gullies were selected from three types and distributed in different topographic and soil characteristics. The associated relationships were then established. The results of topographic characteristics showed that the relation between slope and drainage area of linear gullies in rangeland areas was negative. The critical threshold for gully development for slope of 12% was 6ha verifying more important role of surface runoff in formation and development of gullies. Whereas, no significant relationship could be developed between slope and drainage area of frontal and digitated gullies. It verified the effects of other factors rather surface runoff. The results of studying gullies in different geologic formations also revealed that the sub-surface runoff played an important role in Gsachsaran and quaternary formations in formation and development of gullies. Whereas, the Hortonian runoff caused gully development in Pabadeh geologic formation. The soil sodium, silt and sand contents were also the affecting factors on gully topography with reverse relation with drainage area of the gullies. |
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Keywords: Gully Erosion, Gully Topography, Slope–Area Relationship and Soil Erosion |
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Full-Text [PDF 219 kb]
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Type of Study: Research |
Subject:
Special Received: 2014/03/2 | Accepted: 2014/03/2 | Published: 2014/03/2
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